Arbor and sleeve for mounting same



June 18, 1957 E. A. ARP

ARBOR AND SLEEVE FOR MOUNTING SAME 2 Sheets-Sheet 1 Filed Feb. 16, 1955IN VEN TOR. fun A. 4R?

Arronytrs 1June 18, 1957 Filed Feb. 1e,

E. A. ARP

, ARBOR AND SLEEVE FOR MOUNTING SAME FIE4 2 Sheets-Sheet 2 FIEZS g \A 3231 I l United States Patent l ARBOR AND SLEEVE FOR MOUNTING SAME EwaldA. Arp, Minneapolis, Minn., assignor to Tobin-Arp Manufacturing Company,Minneapolis, Minn., a corporation of Minnesota Application February 16,1955, Serial N 0. 488,588

4 Claims. (Cl. 51-241) This invention has relation to a tapered arborand an expanding sleeve for mounting the arbor.

The invention will find use wherever it is desirable to mount an arborin a generally cylindrical opening to have the axis of the arborcoincident with the axis of the opening. It will be particularly useful,however, where the arbor is to be supported by means of the expandingsleeve in a valve stem guide for locating a grinding wheel to be used ingrinding a valve seat of an internal combustion engine.

When it becomes desirable or necessary to regrind a valve seat in anautomobile engine or other internal combustion engine, it is usually thecase that the valve stem guide has become worn. In some cases, the guidewill be so worn that it must be removed and replaced; and in some cases,it will not be replaced. Whichever of these situations prevail, it isimperative that the valve seat be ground by a grinding wheel which isupported on an axis coincident with the axis of the valve stem whichwill later operate in the valve stem guide.

The arbor and the expanding sleeve for mounting the same must be suchthat the grinding wheel can be supported on the arbor in this positionregardless of whether the valve stem guide is worn and the boretherethrough is no longer exactly cylindrical or whether the valve stemguide is a new replacement with an exactly cylindrical boretherethrough.

In order to accomplish the desired result, a tapered arbor is employedin conjunction with a sleeve having a thin flexible outer wall and aplurality of tapered longitudinal ribs extending radially inwardly fromsaid wall. The sleeve is designed so that the outer surface thereof willalways be cylindrical. There is a longitudinally extending gap in thewall of the sleeve to allow for expansion thereof.

When the expanding sleeve has been placed in the bore of a valve stemguide or in a similar opening with the thin ends of the tapered ribsuppermost, the tapered arbor will be placed inside of the sleeve withits thin end down. The arbor is rung into place to force the ribsoutwardly to cause the outer wall of the sleeve to be expanded as aperfect cylinder of ever increasing diameter until it comes in contactwith the inner surface of the valve stem guide bore. Since the axis ofthe arbor is always coincident with the axis of the sleeve, when thearbor and sleeve are tightly in said opening or bore the arbor will bepositioned so that the grinding wheel can be supported thereon and thevalve seat grinding action commenced.

Since it is often difficult or impossible to gain access to the areaadjacent the end of the valve stem opposite the valve seat, a spider isprovided on the outer end of the tapered arbor which has outwardlyextending teeth thereon which can be brought in contact with the ribs ofthe sleeve to pull the sleeve out of the valve stem guide when the valveseat grinding operation is completed.

Since the diameters of the bores through valve seat 2,795,994 PatentedJune 18,

guides may vary over a considerable range from guide to guide and fromengine to engine, a number of expanding sleeves having tapered ribs ofdifiering radial dimension can be utilized with a single arbor to covera variety of different bores.

In the drawings,

Fig. l is a side elevational view of a portion of an internal combustionengine block with parts in section and parts broken away showing therelationship of an arbor and sleeve for mounting the same made accordingto the present invention to a valve stem guide in said engine block andto a valve seat grinding wheel mounted on said arbor;

Fig. 2 is an enlarged horizontal sectional view taken on the line 22 inFig. 1;

Fig. 3 is an enlarged fragmentary sectional view taken on the line 33 inFig. 2 and disclosing a new valve stem guide which is not worn and whichhas an exactly cylindrical bore therethrough;

Fig. 4 is an enlarged fragmentary sectional view taken on the line 33 inFig. 2, but disclosing a valve stem guide which has become worn;

Fig. 5 is a vertical sectional view of the parts as seen in Fig. 4 butomitting the grinding wheel and disclosing the relative positioning ofthe parts when the arbor is being used to remove the expanding sleevefrom the valve stem guide; and V Fig. 6 is an enlarged fragmentarybottom elevational view taken on the line 66 in Fig. 5.

Referring to the drawings and the numerals of reference thereon, anarbor 10 consists of a cylindrical shaft 11 and a tapered shank 12integral with and in alinement with said shaft. An end portion of saidcylindrical shaft 11 is spaced from said shank 12 and is provided with ahole 13 therethrough. A spider 14 having radially outwardly extendingteeth 15 is fastened to an end of the tapered shank 12 opposite saidcylindrical shaft 11 by the cap screw 16.

An expanding sleeve 17 consists of a thin flexiblewall 18 having acylindrical outer surface and a plurality of tapered longitudinal ribs19 extending radially inwardly from said wall. The wall 18 is broken bya gap 20 which extends longitudinally the entire length thereof. Ashoulder 21 extends outwardly from the entire periphery of the wall 18at an end of said sleeve 17 opposite the thickest portion of the ribs.The taper of the ribs 19 from their thickest portion to the shoulder 21at the opposite end of the sleeve is exactly the same as the taper ofthe tapered shank 12. The main body of the spider 14 is of diameter lessthan the smallest diameter circumscribed by the inner most edges of theribs 19 while the outer dimension of the teeth 15 on said spider is lessthan the diameter of the inner surface of the wall 18 and greater thanthe smallest diameter circumscribed by said inner most edges of saidribs. The width of each tooth 15 is less than the distance between eachof the ribs 19.

A rotary grinding wheel 22 is connected through the outer shell 25 to ahexagonal coupler head 26. The shell 25 is mounted on bearings 23 and'24 and these bearings are slidably supported on the cylindrical shaft11 of the arbor 10. A driving socket of an electric motor (not shown)can be fitted down over the hexagonal coupler head 26 to cause therotary grinding wheel 22 to be rotated.

An engine block 27 of the internal combustion engine presents a surface28 at which valve seats such as 29 are formed. A usual valve stem guide30 having a bore 31 therethrough is illustrated in Figs. 1 and 3 and asimilar valve stem guide 32 having a bore 33 therethrough is illustratedin Figs. 4 and 5. The valve stem-guide 30 is illustrated as being as yetunused and the bore 31 is consequently exactly cylindrical in shapewhile the valve stem guide 32 is illustrated as being one which has seenconsiderable wear and the bore 33 therethrough is no longer exactlycylindrical in shape.

As seen in Figs. 4 and 5, a portion of the valve stem guide 32 adjacentthe valve seat 29 on the right side of each figure has been worn awayleaving a void designated 34. Since this void was worn into the valvestem guide 32 by the action of an originally cylindrical valve stem, aswould be expected, a corresponding void 35 has been formed at theopposite end of the guide and on the left side of each of the figures.

As has been previously stated, in order to mount the arbor 10 in boresof varying size and varying degrees of wear, it is necessary to utilizeone of a number of expanding sleeves such as 17. The normal exteriordimension of the cylindrical wall 18 of each of these sleeves 17 will bedifferent from that of other sleeves but this will be compensated for byusing ribs 19 of sufficient thickness so that the normal interiordimensions of each sleeve will be the same as the outer surface of thetapered shank 12.

In order to mount the arbor 10 to have its axis coincident with the axisof a valve stem which will later operate in the valve stem guide, andexpanding sleeve 17 is chosen which has dimension such that it can beslid into the valve stem guide to allow the shoulder 21 toocome incontact with the outer end of said guide. With the sleeve in thisposition, arbor 10 is inserted into the sleeve until the outer surfaceof the tapered shank 12 is in contact with the inner surfaces of thetapered longitudinal ribs 19. T do this, the teeth 15 must be alinedwith the space between the ribs 19 until the lower end of the taperedshank is below the lower end of the expanding sleeve. A rod 36 isinserted in the hole 13 of the cylindrical shaft 11 of the arbor andthis rod is used as a grip to manually ring the arbor tightly intoplace. This means that the rod 36 is used to push the arbor in directiontoward the valve stem guide while at the same time rotating orattempting to rotate it. The action of the tapered shank 12 on thetapered longitudinal ribs 19 is to cause these ribs to force the thincylindrical wall 18 of the expanding sleeve 17 outwardly. Since theforce on all of the ribs is identical, the outer surface of the wall 18will be caused to expand as a perfect cylinder of ever increasingdiameter.

In the case of the valve stem 30 which has an exactly cylindrical bore31 therethrough, the sleeve 17 will quit expanding when the outersurface of the cylindrical wall 18 is everywhere in contact with theinner surface of the bore 31. When this condition is reached, the axisof the arbor will be exactly coincident with the axis of the bore 31.Since the grinding wheel 22 is rotated and supported about the sameaxis, the axis of the valve seat 29 will also be coincident therewith.It is then obvious that when the arbor and sleeve are removed and avalve is positioned to have the valve stem thereof in the valve stemguide 30, the valve will seat exactly with the valve seat 29.

In the case of the valve stem guide 32, however, the outer surface ofthe thin wall 18 will continue to expand as a perfect cylinder untilsome part of that surface comes into contact with the non-cylindricalbore 33. Since wear is generally effected in the valve stem guidebecause of a sideways tipping of the valve stem, it is to be expectedthat portions of the valve stem bore 33 of the valve stem guide 32 willbe virtually unworn and will still be cylindrical in shape. As the outersurface of the cylindrical wall 18 comes into contact with the unworn orvirtually unworn portions of the bore 33, the outward expansion of thesleeve 17 will stop and the arbor will then be positioned with its axiscoincident with the axis of a valve stem which will later operate in thevalve stem guide In the event that the valve stem guide 32 is so wornthat the bore 33 does not have sufiicient cylindrical areas left tocause the arbor to be positioned coincident with its original axis thearbor will still be positioned coincident with the axis of a valve stemwhich will later operate in the valve stem guide. In other words, theouter surface of the thin wall 18 will expand outwardly as a perfectcylinder of ever increasing diameter until it comes into contact withenough surface of the bore 33 to determine the position of the largestperfect cylinder which can fit into the worn bore and to permanentlyposition it to have its axis coincident with the axis of such a cylinderand, at the same time, to permanently so position said arbor. Thegrinding wheel 22 will be supported on the arbor as described above andthe valve seat 29 will then be ground. When the arbor and the expandingsleeve have been removed, a valve will be placed to have its valve stemin the valve stem guide 32. This valve will have a valve stem largerthan the original valve stem since the bore 33 has been enlarged throughwear. The surfaces of the bore 33 which limited the expansion of thesleeve 17 and determined the positioning of the axis of the arbor Itwill be exactly the same surfaces which determine the positioning of thevalve stem as it reciprocates in the valve stem guide 32. This meansthat the valve will be properly positioned with respect to the valveseat 29 and the fact that this is coincident or not coincident with theaxis of the original bore of the valve stem guide is in no way importantsince a perfect fit has again been obtained.

Before the present invention, it was the usual practice to attempt toproperly position arbors such as 19 by 10- cating various forms oftapered shanks in the bores of valve stem guides. These older methodshave been found objectionable since they do not make use of acylindrical shape in determining the axis about which the valve seat isto be ground. It is to be understood that only an ever expandingcylindrical shape can locate the arbor to have its axis coincident withthe axis of the valve stem which is later to operate in the valve stemguide since the valve stem is also cylindrical in shape. This failure toso locate the two axes caused the grinding of a valve seat which was notcoincident with the axis of a valve operating thereon. This causes suchtroubles as oil pumping, noisy tappets, lazy engines and valve stemfriction.

When the valve seat 29 has been properly ground as described in thespecification, the rotary grinding wheel 22 and its associated mechanismis removed from the cylindrical shaft 11 of the arbor 10 and the rod 36is reinserted into the hole 13 of said shaft. With the use of the rod36, the arbor 10 is rotated and moved in di rection away from the valvestem guide. Once the arbor 10 has been loosened, it is alined in such away that the teeth 15 of the spider 14 are in adjacent contactingrelationship with the bottom edges of the ribs 19 and the arbor 10 isagain moved in direction away from the valve stem guide to cause thesleeve 17 to be removed from the valve stem guide.

What is claimed is:

1. The combination with a guide having an approximately cylindricalopening therethrough of an arbor having a cylindrical shaft and atapered shank concentric with said shaft tapering from a larger portionadjacent said shaft to a smaller outer end portion, an expanding sleevehaving a flexible wall provided with an outer cylindrical surface, ashoulder at one end thereof extending outwardly from said wall, and aplurality of spaced apart, parallel, tapered longitudinal ribs integralwith and extending radially inwardly from said wall, the inner surfaceof said ribs being of configuration and dimension to exactly contact theouter surface of said tapered shank throughout their length, there beinga longitudinally extending gap in said thin wall from end to endthereof, said wall being capable of being expanded outwardly to preservethe outer surface thereof as a perfect cylinder of increasing diameter,said outer expansion being caused by the force of said tapered shank onsaid tapered ribs as the tapered shank is moved into the said sleeve indirection toward the smaller outer end portion of said shank to cause anouter surface of said wall to contact at least a portion of said innersurface of said opening, a plurality of teeth extending outwardly fromsaid outer end portion of said shank, outer edges of said teethextending to a diameter less than the diameter of the inner surface ofsaid wall and greater than the smallest diameter of said ribs, the widthof said teeth being less than the space between said teeth.

2. The combination with a guide having an approximately cylindricalopening therethrough of an arbor having a cylindrical shaft and atapered shank concentric with said shaft tapering from a larger portionadjacent said shaft to a smaller outer end portion, an expanding sleevehaving a flexible wall provided with an outer cylindrical surface, ashoulder at one end thereof extending out wardly from said wall, and aplurality of spaced apart, parallel, tapered longitudinal ribs integralwith an extending radially inwardly from said wall, the inner surface ofsaid ribs being of configuration and dimension to exactly contact theouter surface of said tapered shank throughout their length, there beinga longitudinally extending gap in said thin wall from end to endthereof, said wall being capable of being expanded outwardly to preservethe outer surface thereof as a perfect cylinder of increasing diameter,said outer expansion being caused by the force of said tapered shank onsaid tapered ribs as the tapered shank is moved into the said sleeve indirection toward the smaller outer end portion of said shank to cause anouter surface of said wall to contact at least a portion of said innersurface of said opening, a plurality of teeth extending outwardly fromsaid outer end portion of said shank, outer edges of said teethextending to a diameter less than the diameter of the inner surface ofsaid wall and greater than the smallest diameter of said ribs, the spacebetween said teeth being greater than the width of said ribs.

3. The combination with a guide having an approximately cylindricalopening therethrough of an arbor having a cylindrical shaft and atapered shank concentric with said shaft tapering from a larger portionadjacent said shaft to a smaller outer end portion, an expanding sleevehaving a flexible wall provided with an outer cylindrical surface, ashoulder at one end thereof extending outwardly from said wall, and aplurality of spaced apart, parallel,

6 tapered longitudinal ribs integral with and extending radiallyinwardly from said wall, the inner surface of said ribs being ofconfiguration and dimension to exactly contact the outer surface of saidtapered shank throughout their length, there being a longitudinallyextending gap in said thin wall from end to end thereof, said wall beingcapable of being expanded outwardly to preserve the outer surfacethereof as a perfect cylinder of increasing diameter, said outerexpansion being caused by the force of said tapered shank on saidtapered ribs as the tapered shank is moved into the said sleeve indirection toward the smaller outer end portion of said shank to cause anouter surface of said wall to contact at least a portion of said innersurface of said opening, and a projection extending outwardly from saidouter end portion of said shank, outer edges of said projectionextending to a diameter less than the diameter of the inner surface ofsaid wall and greater than the smallest diameter of said ribs.

4. The combination with a guide having an approximately cylindricalopening therethrough of an arbor having a cylindrical shaft and atapered shank concentric with said shaft tapering from a larger portionadjacent said shaft to a smaller outer end portion, an expanding sleevehaving a flexible wall provided with an outer cylindrical surface, ashoulder at one end thereof extending outwardly from said wall, and aplurality of spaced apart, parallel, tapered longitudinal ribs integralwith and extending radially inwardly from said wall, the inner surfaceof said ribs being of configuration and dimension to exactly contact theouter surface of said tapered shank throughout their length, there beinga longitudinally extending gap in said thin wall from end to endthereof, said wall being capable of being expanded outwardly to preservethe outer surface thereof as a perfect cylinder of increasing diameter,said outer expansion being caused by the force of said tapered shank onsaid tapered ribs as the tapered shank is moved into the said sleeve indirection toward the smaller outer end portion of said shank to cause anouter surface of said wall to contact at least a portion of said innersurface of said opening.

References Cited in the file of this patent UNITED STATES PATENTS1,775,898 Fleming Sept. 16, 1930 1,777,047 Meon Sept. 30, 1930 1,950,522Seelert Mar. 13, 1934 2,044,474 Groetchen June 16, 1936

